The present invention relates generally to flexible wing aircraft, and more particularly to single surface membranous lifting surfaces deployable from the fuselage of an aircraft for controlling the flight.
Single surface flexible lifting surfaces or airfoils, commonly used in hang gliders are considered excellent candidates for many other applications due to their low cost and simplicity of construction. For example, they may serve as the primary lifting surfaces on air launched torpedoes and aerial targets. Due to their ability to be folded and stored in the fuselage of a vehicle, such airfoils are also suitable as auxillary lifting surfaces on electronic countermeasure decoys and remotely piloted vehicles (RPV's) for reducing their speed for loitering or recovery on surface vessels.
However, there has been virtually no in-flight adjustment of membranous airfoils for control purposes. In hang gliders, for instance, flight is controlled primarily by a pilot shifting his weight or changing the wing planform. Previous efforts to construct a full scale membranous wing system for unmanned vehicles resulted in complex vibration problems due to membrane flutter. These deficiencies among others, has impeded the use of single surface membraneous airfoils for these other applications.